I havent been to either of the sites. But im not far from Dulverton and i've holiday'ed at Looe several times.
Dulverton is almost on Exmoor, of course its very pretty and scenic and your a short drive to the north coast resorts of Lynton, Lynmouth, Porlock, Minehead and Dunster Beach, so lots of beaches to exlpore. The inland villages of Dulverton, Bampton, Dunster, Exford are all very pretty with your usual country pubs and little shops etc. (Dunster is very pretty and you have Dunster Castle to explore). I would say the best things to do in this area are walking, fishing,exploring the area, days out on the moor, beaches etc. For the kids a nice day out is taking the steam train to Minehead (starts from Bishops lydeard in somerset) which winds its way through the countryside along the coast to minehead itself. You could go into Butlins if you want a bit more action and the kids could enjoy the rides/amusements etc.
Looe is very nice also, lots of lovely beaches in the area, cornish fishing villages to explore. You could do the Eden project if you havent done that yet. For the kids - if you want to drive further down - you have Flambards theme park near Helston, and the seal sanctuary at Gweek. Lots to do, you can be as relaxed or active as you want.